Identifying amyloidogenic proteins and amyloidogenic risk

Immunoglobulin light chain proteins are used to generate synthetic fibrils in vitro. The fibrils are mixed with immunoglobulin light chain proteins from a biological sample. In either a direct binding assay, competition assay, or dilution-based competition assay, a signal is detected from the mixture. The intensity of the detectable signal relates to the level of binding between the immunoglobulin light chain proteins to the fibrils and can thus be used to identify amyloidogenic immunoglobulin light chain proteins in a biological sample of the subject and to assess amyloidogenic risk to a subject. For example, the signal intensities from the assays can be used in a comparison to one or more threshold (control) values derived from samples of known light chain types or in the absence of light chains. The comparisons permit identification of amyloidogenic proteins, assessment of amyloidogenic risk, and categorization of the subject into an appropriate “at risk” group.